Computational study of graphene flakes for carbon capture

Abstract

We study numerically the adsorption of a mixture of CH4, CO2, and N2 at room temperature on a substrate composed of graphene flakes. Our study is based on Molecular Dynamics and Monte Carlo simulations. Methane is considered a spherical molecule, carbon dioxide and nitrogen are represented as linear rigid bodies, and the substrate is rigid and fixed. Our simulations of N2 at 77 K and CO2 at 273 K on the substrate are compatible with the experimental isotherms in activated carbons. We consider different concentrations for the mixtures and show that the substrate is adequate for the separation and adsorption of CO2. On average, CO2 is adsorbed 6.5 more than the other components in a ternary mixture CO2/CH4/N2. The rate of adsorption of CO2 is higher than CH4 and N2 in all the mixtures studied.